1. Field of the Invention
The present invention relates to a tilting type chair, and more particularly, to a tilting type chair in which a seat of the chair is movable up and down depending on a direction of a load or movement applied to a back support of the chair by a user and tilting is capable of being limited as needed.
2. Description of the Prior Art
Conventionally, comfort is considered to be one of the most important factors in a chair because a user should be able to be seated thereon for a long time. However, because a place in which such a chair is used may be changed due to, for example, frequent removal, portability and lightweight are recently preferred. Thus, simple chairs are in the spotlight of consumers. However, apart from excellence in portability and lightweight, such a simple chair such has a problem in that it is poor in comfort as compared to a large chair. Whereas, in large chairs, a seat, a back rest and/or arm rests have been provided with a soft cushion for the user's comfort, and the seat and the back rest are configured to be capable of rotating integrally in a state where the legs of the chair are fixed, and thus, the large chairs have been remarkably improved in comfortability.
Many large chairs are provided with a tilting function such that, when a user bends his/her upper body backwards on a large chair, the back rest of the chair is bent backwards in a state where the center of gravity of the chair is maintained, and when the external force applied by the user is removed again, the back rest is returned to its original position.
However, in order to ensure that the tilting function can be executed in a large chair, a means for providing a restoring force, such as a coil spring, is essential for the chair, and the configuration thereof is very complicated. Thus, it is not easy for a person to assemble the chair when the person is not skilled in assembly.
When the tilting means applied to a large chair as described above is applied to a simple chair, a complicated configuration is applied to the simple chair. As a result, the versatility of the simple chair is degraded and the weight of the simple chair is increased, which makes it difficult to adopt the tilting means in the simple chair. Even if the tilting means is applied to the simple chair in such a manner as to suppress an increase of the weight of the simple chair, the tilting function cannot be properly performed because it is not easy to maintain the center of gravity. Further, when the chair is tilted, a seating feeling on the seat is degraded so that the user may feel uncomfortable.
Meanwhile, Korean Laid-Open Patent Publication No. 2003-0059582 discloses a tilting type chair applied to a simple chair, which has been made so as to solve a problem that a user's entire upper body cannot be supported uniformly since a space is produced between a back rest and the user's lumbar vertebrae when the back rest is tilted. For this purpose, the chair disclosed in Korean Laid-Open Patent Publication No. 2003-0059582 is designed such that when the user bends his/her back backwards to tilt the back rest frame, the back rest frame can be deformed to fully support the lumbar vertebrae. However, the chair disclosed in Korean Laid-Open Patent Publication No. 2003-0059582 has a problem in that a separate complicated link structure should be provided in order to allow the back rest frame to be deformed.